In pharmaceutical, genomic, and proteomic research, biology research, drug development laboratories, and other biotechnology applications, a liquid pipette is used to handle laboratory samples in a variety of laboratory procedures. Using a pipette, a volume of liquid is aspirated into the pipette. The volume of liquid may then be dispensed in one or more dispensation volume. A piston drive mechanism controls the aspiration and the dispensation of the liquid in specified volumes by imparting motion to a piston assembly. Pipettes in which the piston assembly within the body of the pipette includes a piston rod controlled by either a motor or directly by the user are known to those skilled in the art. Motion of the piston rod is controlled by a thrust exerted by the piston drive mechanism. However, angular displacement of components within the piston drive mechanism may occur relative to the piston assembly. The displacement often causes a small, but measurable longitudinal shift of the piston drive mechanism that in turn causes an inaccurate aspiration or dispensation of the volume of liquid. Thus, what is needed, is a pipette that eliminates the unwanted longitudinal displacement of the piston drive mechanism components.
A pipette may operate in a manual mode wherein the user manually controls the speed and the volume of aspiration or of dispensation of the liquid using a pressure sensitive knob. Alternatively, a pipette may operate in an electronic mode wherein a motor controls the aspiration and/or dispensation of the liquid. The user may select various parameters including a speed, a volume, a number of aspirations, a number of dispensations, etc. using a user interface. The user interface may include a numeric keypad that allows the user to enter, for example, the volume. A pipette generally is small and lightweight because the desire is for an easily portable device that fits comfortably into a hand of the user and that can be used repetitively with a single hand. As a result, the display and the operational controls must be small making them generally tedious to use. For example, some pipettes may have the small numeric keypad, while the input to other pipettes may be through a set of buttons such as up and down arrow buttons to increase or to decrease a parameter. However, the numeric keypad is difficult to use because each numerical button is small and difficult to select particularly when a user is wearing gloves. Also, use of the keypad buttons generally requires the use of both hands. One hand to support the device and the other hand to precisely select the appropriate numerical button. Additionally, the user may need to successively dispense widely-differing volumes. The up and down arrow buttons require a large number of depressions to reach, for example, the widely-differing volume amount. Thus, what is needed is a pipette having an input interface that simplifies the selection of operational parameters for the device and that reduces the time required to change settings within the device. What is further needed is an input interface that can be operated using a single hand.
Electronic pipettes typically are controlled by small microprocessors placed within the housing of the pipette. As electronic pipettes have become more sophisticated, additional and more complex operational modes may be provided. For example, an electronic pipette may be configured to aspirate a volume of liquid and dispense the volume in successive dispensation cycles. Additionally, an electronic pipette may be configured to repeatedly aspirate and dispense a volume of liquid thereby mixing the liquid before the final dispensation of the liquid. To add additional complexity, a sequence of modes may be provided to execute in succession. Again, however, the display and the operational controls are small and tedious to use making it more difficult to “program” the electronic pipette to perform a complex sequence of operations. Thus, what is needed is a pipette that can interface with an external computing device. What is further needed is an application that can be executed on the external computing device to provide an easy to use interface to the user and to provide instructions to the pipette for operation in a “programmed” mode.